Anet A8 PSU cover with switch, relays, fan and OctoPrint

Last crawled date: 4 years, 2 months ago

Just another PSU cover with power switch for Anet A8 printer.
This one can also contain a 2-channel relay board to remotely cut off power to the printer, an Orange Pi Zero Plus to run OctoPrint, a 5V AC/DC to power the Orange Pi, and an 8x8cm fan to cool down the PSU, the Orange Pi and the AC/DC board.
My setup is as follow:
one Orange Pi Zero Plus (probably other versions of Orange Pi Zero can fit)
one SunFounder 2-channel relay module (this one, can be bought on Amazon or AliExpress too, see official wiki for additional details)
one power switch (note: there are two similar versions of this switch, one with countersink screw heads and one without, depending which one you buy, you need to use the right screws)
one AC/DC board (220V to 5V) to power the Orange Pi (of course you can use any 5V AC/DC with enough power, my design is for this one)
one 80x80x25 mm fan (I've used an old Coolermaster fan, but other fans like this or this should fit, I've powered it with 5V instead of 12V, the spin speed is enough)
To mount the whole box you also need:
screws
2 screws M3x10mm countersink head (for switch)
10 screws M3x12mm countersink head (for switch reinforce, AC/DC board and Orange Pi board)
4 screws M3x18mm countersink head (for relay module)
7 screws M3x10mm round head (for front and right box panels)
1 screws M3x18mm round head (for left box panel)
2 screws M4x16mm round head (for fan, note: these are M4, not M3)

nuts
23 M3 nuts
2 M4 nuts

wires
16-18 AWG 220V wires for neutral, line and ground (from plug to internal fuse, from fuse to switch, from switch to relay and from relay to PSU)
22 AWG 220V wires for neutral and line (from fuse to AC/DC, note: the AC/DC is directly connected to the fuse bypassing the switch, this way the Orange Pi is always on)
22 AWG 5V wires for Vcc and GND (from AC/DC to Orange Pi)
6 dupont wires female-female (from Orange Pi to relay)

connectors and other
one 2-pin PCB screw terminal (like this one for AC/DC 220V input)
two 2-pin JST couple male+female (for AC/DC 5V output and for fan input)
one micro usb male connector (from AC/DC JST output to Orange Pi input)
one 2A fuse to be installed inside the power switch
one small switch (not needed) to switch on/off the fan (you can also use a transistor switch controlled by an OPi's pin)

I will attach a schematic diagram as soon as I have free time to design it.
WARNING
Unfortunately I discovered that the location of the Orange Pi is not optimal because the USB cable to the Anet board suffers interference (EMI) from the PSU. So I moved the OPi above the PSU attaching it to the Anet frame with this simple holder. All the interference disappeared.